bad Company, without doubt the top gym in the world outside thailand for consistently producing world class fighters that take on top thais as well as other international and domestic opponents. liam Harrison alone has in the last 5 years fought Numphon PK Stereo twice, Anuwat keawsamrit twice, Seanchai twice, Sagetdao and has just won the WBC title in America in addition to all his other belts that were fought against very hard opposition. Add Jordan Watson, Andy Howson, Richard Cadden, James France, Davey Mac, Lisa Houghton-Smith, Sarah McCarthy, Charlotte Webster etc the list is endless. Richard Smith also was a good fighter but an even better coach.
Wicker Camp another very good gym that has produced top drawer fighters like Helene Garnett, Tommi McC, Christian Di Paulo, Trix March etc.
Keddles gym another very good gym especially for producing great female fighters, as is KO gym in london.
but there are very good thai boxing coaches all over the UK, even those that dont put fighters out all the time. Paul Pearson is an excellent coach and doesnt get enough of a mention in Thai Boxing, he has massive amounts of knowledge and has spent years and years in thailand learning from a lot of different people there.